This project was undertaken to elucidate the biochemical basis for the acute lung toxicity of 4-ipomeanol (IPO), a naturally occurring furan derivative. It is now apparent IPO produces pulmonary necrosis due to its metabolism to an alkylating agent in the target tissue. In continuing studies we are investigating the toxication and detoxication pathways available to IPO and the chemical nature of its toxic electrophilic metabolite(s).